Quick answer: A modern residential solar panel measures roughly 66–82 inches long, 40–45 inches wide, and 1. 6 inches thick, weighs 40–55 lb, and produces 350–460 watts. The full size-by-wattage. A 400W panel has the same physical footprint whether it produces 350W or 450W – the difference lies in cell efficiency and technology. However, the exact dimensions depend heavily on the panel's technology, wattage, and the manufacturer's design. Fortunately, most sloped residential roofs in the UK are strong enough to support the weight. Most residential solar panels are about 65 × 39 inches, while many commercial solar panels are larger, often around 79 × 39 inches or more. Some are ultra-efficient and compact; others are larger but deliver less per square metre.
